1. Field of the Invention
This invention relates to linkages for rotatably joining two parts of a structure together, and specifically provides for two members to be joined together in a first attitude until, on deployment for example, they are released and automatically take up a second, rigid attitude.
2. Discussion of Prior Art
Such linkages are known and used, for example, for folding rod or tubular members of a structure intersected by nodes. The object in this arrangement is for the structure to be folded into a minimum volume for transportation, and for it to open automatically into a specific, fixed relationship when required. A particular requirement for this is the deployment of skeletal structures used as space platforms: these have to be stowed as compactly as possible in the launch vehicle and need to be erected reliably and as automatically as possible. The types of joint used hitherto for such purposes have usually been bulky, have required additional components to restrain the initial impulsion rate, and have contained separate locking elements.